| 摘要 |
PURPOSE:To efficiently produce optical fiber of uniform composition by a method wherein liquid for cleaning deposited oxide is introduced downstream of gas flow in reaction tube to make flow rate of raw material gas constant in glassification process by melting oxide soot on the inner surface of silica reaction tube. CONSTITUTION:Preform rod forming silica reaction tube 1 is joined with support tube 2 and rotated. Raw material such as GeCl4 carried by Ar or O2 gas is introduced from inlet B at a specified flow rate. H2-O2 burner 4 is moved in parallel so that raw gas is oxidized, oxidized soot 5 is formed on the inner surface of the support tube 2, and melted into glass. At this time, cleaning liquid is projected from fine silica tube 6 in the support tube 2 to clean unmelted oxide soot which is flowed with decomposed waste gas and likely blocks gas passage by depositing on the inner wall of the tube 2. The soot is discharged to container 8. In this manner, the flow rate of raw gas is made to constant and uniform-composition preform rod is efficiently provided. |
